from __future__ import annotations

import argparse
import os
import re
import subprocess
import sys
import tomllib
from dataclasses import dataclass
from pathlib import Path
from typing import Any, Sequence

DEFAULT_FRAMEWORK_GIT = os.environ.get(
    "ITICLI_FRAMEWORK_GIT",
    "https://git.noahlan.cn/iti-framework/iTi-Flask.git",
)
DEFAULT_SYSTEM_GIT = os.environ.get(
    "ITICLI_SYSTEM_GIT",
    "https://git.noahlan.cn/iti-framework/iTi-System.git",
)
DEFAULT_COPIER_REF = os.environ.get("ITICLI_COPIER_REF", "HEAD")

ENV_NAMES = {"dev", "test", "prod", "default"}


class CliError(Exception):
    def __init__(self, message: str, code: int = 2) -> None:
        super().__init__(message)
        self.code = code


@dataclass(frozen=True)
class ProjectContext:
    root: Path
    kind: str
    pyproject: dict[str, Any]
    has_system: bool


def main(argv: Sequence[str] | None = None) -> int:
    parser = build_parser()
    args = parser.parse_args(argv)
    try:
        return int(args.handler(args))
    except CliError as exc:
        print(str(exc), file=sys.stderr)
        return exc.code


def build_parser() -> argparse.ArgumentParser:
    parser = argparse.ArgumentParser(
        prog="iticli",
        description="iTi-Flask framework and business project CLI.",
    )
    parser.set_defaults(handler=lambda _args: parser.print_help() or 0)

    subparsers = parser.add_subparsers(dest="command")

    help_parser = subparsers.add_parser("help", help="show help")
    help_parser.set_defaults(handler=lambda _args: parser.print_help() or 0)

    install_parser = subparsers.add_parser("install", help="install project dependencies")
    install_parser.add_argument(
        "profile",
        nargs="?",
        choices=["dev", "odbc"],
        help="dev installs project dev dependencies; odbc also installs pyodbc",
    )
    install_parser.set_defaults(handler=handle_install)

    test_parser = subparsers.add_parser("test", help="run tests")
    test_parser.set_defaults(handler=handle_test)

    add_run_parser(subparsers, "run")
    add_run_parser(subparsers, "serve")

    migrate_parser = subparsers.add_parser("migrate", help="run Alembic commands")
    migrate_parser.add_argument("action", nargs="?", help="upgrade target, heads, current, revision, ...")
    migrate_parser.add_argument("args", nargs=argparse.REMAINDER)
    migrate_parser.add_argument("-m", "--message", help="migration message for revision")
    migrate_parser.set_defaults(handler=handle_migrate)

    create_parser = subparsers.add_parser("create", help="create a business project")
    create_parser.add_argument("project_name", help="target directory or project name")
    create_parser.add_argument("--with-system", action="store_true", help="include iti-system")
    create_parser.add_argument("--target", help="target directory, defaults to project_name")
    create_parser.add_argument("--slug", help="distribution/project slug, defaults to target basename")
    create_parser.add_argument("--display-name", help="business project display name")
    create_parser.add_argument("--source", help="Copier template source, defaults to iTi-Flask private Git")
    create_parser.add_argument("--ref", default=DEFAULT_COPIER_REF, help="Copier source ref, defaults to HEAD")
    create_parser.add_argument("--local", action="store_true", help="use current iTi-Flask framework checkout as template source")
    create_parser.add_argument("--framework-git", help="framework dependency Git URL rendered into the project")
    create_parser.add_argument("--framework-tag", help="framework dependency tag rendered into the project")
    create_parser.add_argument("--system-git", help="system dependency Git URL rendered into the project")
    create_parser.add_argument("--system-tag", help="system dependency tag rendered into the project")
    create_parser.set_defaults(handler=handle_create)

    release_parser = subparsers.add_parser("release", help="release iTi-Flask framework")
    release_parser.add_argument("version", nargs="?", help="target version, defaults to next patch")
    release_parser.set_defaults(handler=handle_release)

    sync_parser = subparsers.add_parser("sync", help="sync framework or system package")
    sync_parser.add_argument("target", choices=["flask", "system", "all"], nargs="?", default="all")
    sync_parser.set_defaults(handler=handle_sync)

    template_parser = subparsers.add_parser("template", help="check or update Copier template")
    template_subparsers = template_parser.add_subparsers(dest="template_action", required=True)
    template_check = template_subparsers.add_parser("check", help="check template updates")
    template_check.set_defaults(handler=handle_template)
    template_update = template_subparsers.add_parser("update", help="apply template updates")
    template_update.set_defaults(handler=handle_template)

    init_parser = subparsers.add_parser("init", help="initialize a business project")
    init_parser.add_argument("scope", nargs="?", choices=["system"], help="only run system migration and seed")
    init_parser.set_defaults(handler=handle_init)

    docker_parser = subparsers.add_parser("docker", help="run Docker Compose commands")
    docker_parser.add_argument("action", choices=["build", "up", "down", "logs"])
    docker_parser.add_argument("--db", action="store_true", help="include docker-compose.with-db.yml")
    docker_parser.add_argument("--service", default="app", help="service name for logs")
    docker_parser.set_defaults(handler=handle_docker)

    return parser


def add_run_parser(subparsers: argparse._SubParsersAction[argparse.ArgumentParser], name: str) -> None:
    run_parser = subparsers.add_parser(name, help="run the app")
    run_parser.add_argument("env_or_port", nargs="?", help="dev, test, prod, or port")
    run_parser.add_argument("port", nargs="?", help="port when env is provided")
    run_parser.set_defaults(handler=handle_run)


def handle_install(args: argparse.Namespace) -> int:
    ctx = require_project()
    if args.profile == "odbc":
        extra_name = find_optional_extra(ctx.pyproject, ["odbc", "erp"])
        if extra_name:
            return run(["uv", "sync", "--extra", "dev", "--extra", extra_name], ctx.root)
        code = run(["uv", "sync", "--extra", "dev"], ctx.root)
        if code:
            return code
        return run(["uv", "pip", "install", "pyodbc>=5.3.0"], ctx.root)
    return run(["uv", "sync", "--extra", "dev"], ctx.root)


def handle_test(_args: argparse.Namespace) -> int:
    ctx = require_project()
    if ctx.kind == "business":
        return run(["uv", "run", "--extra", "dev", "pytest", "-q"], ctx.root)
    return run(["uv", "run", "pytest", "-q"], ctx.root)


def handle_run(args: argparse.Namespace) -> int:
    ctx = require_project()
    env_name, port = parse_run_args(args.env_or_port, args.port)
    env = {"APP_ENV": env_name}

    if ctx.kind == "framework":
        cmd = ["uv", "run", "uvicorn", "iti.app:create_app", "--factory", "--port", port]
    else:
        cmd = ["uv", "run", "uvicorn", "main:app", "--port", port]

    if env_name == "prod":
        cmd.extend(["--host", "0.0.0.0"])
    else:
        cmd.append("--reload")

    return run(cmd, ctx.root, extra_env=env)


def handle_migrate(args: argparse.Namespace) -> int:
    ctx = require_project()
    action = args.action
    rest = list(args.args or [])
    base_cmd = alembic_base_cmd(ctx)

    if not action:
        return run([*base_cmd, "upgrade", "head"], ctx.root)

    if action in {"revision", "migration"}:
        message = args.message or extract_message(rest) or " ".join(rest).strip()
        if not message:
            raise CliError('missing migration message, example: iticli migrate revision "alice add order table"')
        return run([*base_cmd, "revision", "--autogenerate", "-m", message], ctx.root)

    if action == "upgrade":
        target = rest[0] if rest else "head"
        return run([*base_cmd, "upgrade", target, *rest[1:]], ctx.root)

    if action in {"heads", "current", "history", "branches", "downgrade", "stamp", "show"}:
        return run([*base_cmd, action, *rest], ctx.root)

    return run([*base_cmd, "upgrade", action, *rest], ctx.root)


def handle_create(args: argparse.Namespace) -> int:
    cwd = Path.cwd()
    source = args.source or DEFAULT_FRAMEWORK_GIT
    if args.local:
        ctx = require_project({"framework"})
        source = str(ctx.root)

    target = Path(args.target or args.project_name).expanduser()
    if not target.is_absolute():
        target = cwd / target

    slug = args.slug or target.name
    display_name = args.display_name or target.name

    cmd = [
        "uvx",
        "copier",
        "copy",
        "--defaults",
        "--vcs-ref",
        args.ref,
        source,
        str(target),
        "-d",
        f"project_name={display_name}",
        "-d",
        f"project_slug={slug}",
        "-d",
        f"include_system={str(args.with_system).lower()}",
    ]
    if args.framework_git:
        cmd.extend(["-d", f"framework_git={args.framework_git}"])
    if args.framework_tag is not None:
        cmd.extend(["-d", f"framework_tag={args.framework_tag}"])
    if args.system_git:
        cmd.extend(["-d", f"system_git={args.system_git}"])
    if args.system_tag is not None:
        cmd.extend(["-d", f"system_tag={args.system_tag}"])

    return run(cmd, cwd)


def handle_release(args: argparse.Namespace) -> int:
    ctx = require_project({"framework", "system"})
    if ctx.kind == "system":
        return release_system(ctx.root, args.version)
    return release_framework(ctx.root, args.version)


def handle_sync(args: argparse.Namespace) -> int:
    ctx = require_project({"business"})
    if args.target in {"flask", "all"}:
        cmd = ["uv", "sync", "--extra", "dev", "--upgrade-package", "iti-flask"]
        if args.target == "all" and ctx.has_system:
            cmd.extend(["--upgrade-package", "iti-system"])
        code = run(cmd, ctx.root)
        if code:
            return code
    if args.target in {"system", "all"}:
        if not ctx.has_system:
            raise CliError("current business project does not depend on iti-system")
        code = run(["uv", "run", "iti-system", "migrations", "sync", "--target", "migrations/versions"], ctx.root)
        if code:
            return code
    return 0


def handle_template(args: argparse.Namespace) -> int:
    ctx = require_project({"business"})
    cmd = ["uvx", "copier", "update", "--defaults", "--vcs-ref", "HEAD", str(ctx.root)]
    if args.template_action == "check":
        cmd.insert(4, "--pretend")
    return run(cmd, ctx.root)


def handle_init(args: argparse.Namespace) -> int:
    ctx = require_project({"business"})
    if args.scope == "system":
        if not ctx.has_system:
            raise CliError("current business project does not depend on iti-system")
        code = sync_system_migrations(ctx)
        if code:
            return code
        code = run([*alembic_base_cmd(ctx), "upgrade", "head"], ctx.root)
        if code:
            return code
        return seed_system(ctx)

    code = run(["uv", "sync", "--extra", "dev"], ctx.root)
    if code:
        return code
    if ctx.has_system:
        code = sync_system_migrations(ctx)
        if code:
            return code
    code = run([*alembic_base_cmd(ctx), "upgrade", "head"], ctx.root)
    if code:
        return code
    if ctx.has_system:
        return seed_system(ctx)
    return 0


def handle_docker(args: argparse.Namespace) -> int:
    ctx = require_project({"business"})
    compose = ["docker", "compose"]
    if args.db:
        compose.extend(["-f", "docker-compose.yml", "-f", "docker-compose.with-db.yml"])

    if args.action == "build":
        return run([*compose, "build"], ctx.root)
    if args.action == "up":
        return run([*compose, "up", "-d", "--build"], ctx.root)
    if args.action == "down":
        return run([*compose, "down"], ctx.root)
    return run([*compose, "logs", "-f", args.service], ctx.root)


def require_project(allowed: set[str] | None = None) -> ProjectContext:
    ctx = detect_project(Path.cwd())
    if ctx.kind == "unknown":
        raise CliError("current directory is not an iTi-Flask framework or business project")
    if allowed and ctx.kind not in allowed:
        expected = " or ".join(sorted(allowed))
        raise CliError(f"command requires {expected} project, current project is {ctx.kind}")
    return ctx


def detect_project(cwd: Path) -> ProjectContext:
    root = find_project_root(cwd)
    if root is None:
        return ProjectContext(cwd, "unknown", {}, False)

    pyproject = read_pyproject(root / "pyproject.toml")
    project_name = str(pyproject.get("project", {}).get("name", ""))

    is_framework = (
        project_name == "iti-flask"
        and (root / "iti" / "app.py").is_file()
        and (root / "copier.yml").is_file()
    )
    has_flask = has_package(pyproject, "iti-flask")
    has_system = has_package(pyproject, "iti-system")
    is_business = (
        has_flask
        and (root / "main.py").is_file()
        and (root / "app").is_dir()
        and (root / "migrations" / "alembic.ini").is_file()
    )
    is_system = (
        project_name == "iti-system"
        and (root / "iti_system" / "module.py").is_file()
        and (root / "iti_system" / "cli.py").is_file()
    )

    if is_framework:
        kind = "framework"
    elif is_system:
        kind = "system"
    elif is_business:
        kind = "business"
    else:
        kind = "unknown"
    return ProjectContext(root, kind, pyproject, has_system)


def find_project_root(cwd: Path) -> Path | None:
    current = cwd.resolve()
    for path in (current, *current.parents):
        if (path / "pyproject.toml").is_file():
            return path
    return None


def read_pyproject(path: Path) -> dict[str, Any]:
    try:
        with path.open("rb") as file:
            return tomllib.load(file)
    except FileNotFoundError:
        return {}
    except tomllib.TOMLDecodeError as exc:
        raise CliError(f"invalid pyproject.toml: {exc}") from exc


def has_package(pyproject: dict[str, Any], package_name: str) -> bool:
    project = pyproject.get("project", {})
    dependencies = list(project.get("dependencies", []) or [])
    optional = project.get("optional-dependencies", {}) or {}
    for values in optional.values():
        dependencies.extend(values or [])

    normalized = package_name.lower().replace("_", "-")
    for dependency in dependencies:
        name = re.split(r"\s|@|>=|<=|==|~=|!=|>|<|\[", str(dependency), maxsplit=1)[0]
        if name.lower().replace("_", "-") == normalized:
            return True

    uv_sources = pyproject.get("tool", {}).get("uv", {}).get("sources", {}) or {}
    return normalized in {str(key).lower().replace("_", "-") for key in uv_sources}


def find_optional_extra(pyproject: dict[str, Any], names: Sequence[str]) -> str | None:
    optional = pyproject.get("project", {}).get("optional-dependencies", {}) or {}
    normalized = {str(name).lower().replace("_", "-"): str(name) for name in optional}
    for name in names:
        found = normalized.get(name.lower().replace("_", "-"))
        if found:
            return found
    return None


def parse_run_args(env_or_port: str | None, port_arg: str | None) -> tuple[str, str]:
    env_name = os.environ.get("APP_ENV", "dev")
    port = "8000"

    if env_or_port:
        if env_or_port in ENV_NAMES:
            env_name = "dev" if env_or_port == "default" else env_or_port
            port = port_arg or port
        elif env_or_port.isdigit():
            port = env_or_port
        else:
            env_name = env_or_port
            port = port_arg or port

    if port_arg and not env_or_port:
        port = port_arg
    if not str(port).isdigit():
        raise CliError(f"invalid port: {port}")
    return env_name, str(port)


def extract_message(rest: list[str]) -> str | None:
    for flag in ("-m", "--message"):
        if flag in rest:
            index = rest.index(flag)
            if index + 1 >= len(rest):
                raise CliError(f"{flag} requires a message")
            message = rest[index + 1]
            del rest[index : index + 2]
            return message
    for item in list(rest):
        if item.startswith("--message="):
            rest.remove(item)
            return item.partition("=")[2]
    return None


def alembic_base_cmd(ctx: ProjectContext) -> list[str]:
    cmd = ["uv", "run", "alembic"]
    if ctx.kind == "business":
        cmd.extend(["-c", "migrations/alembic.ini"])
    return cmd


def sync_system_migrations(ctx: ProjectContext) -> int:
    return run(["uv", "run", "iti-system", "migrations", "sync", "--target", "migrations/versions"], ctx.root)


def seed_system(ctx: ProjectContext) -> int:
    return run(
        ["uv", "run", "iti-system", "seed", "system", "app:create_app"],
        ctx.root,
        extra_env={"PYTHONPATH": "."},
    )


def run(cmd: Sequence[str], cwd: Path, extra_env: dict[str, str] | None = None) -> int:
    env = project_env(cwd, extra_env)
    completed = subprocess.run(list(cmd), cwd=str(cwd), env=env, check=False)
    return int(completed.returncode)


def project_env(root: Path, extra_env: dict[str, str] | None = None) -> dict[str, str]:
    env = os.environ.copy()
    virtual_env = env.get("VIRTUAL_ENV")
    project_venv = root / ".venv"
    if virtual_env:
        try:
            same_venv = Path(virtual_env).resolve() == project_venv.resolve()
        except OSError:
            same_venv = False
        if not same_venv:
            env.pop("VIRTUAL_ENV", None)
    if extra_env:
        env.update(extra_env)
    return env


def release_framework(root: Path, version_arg: str | None) -> int:
    current_version = read_current_version(root / "iti" / "__about__.py")
    target_version = normalize_version(version_arg) if version_arg else bump_patch(current_version)
    target_tag = f"v{target_version}"

    if target_version == current_version:
        raise CliError(f"version already set to {target_version}")
    if not version_is_newer(current_version, target_version):
        raise CliError(f"target version must be newer than {current_version}")
    if git_output(root, ["status", "--porcelain"]).strip():
        raise CliError("working tree is not clean")

    branch = git_output(root, ["symbolic-ref", "--quiet", "--short", "HEAD"]).strip()
    if not branch:
        raise CliError("release requires a branch checkout")
    if subprocess.run(["git", "rev-parse", "--verify", "--quiet", f"refs/tags/{target_tag}"], cwd=root).returncode == 0:
        raise CliError(f"tag already exists: {target_tag}")

    code = run(["uv", "run", "pytest", "-q"], root)
    if code:
        return code

    write_framework_release_files(root, target_version)

    code = run(
        [
            "git",
            "add",
            "iti/__about__.py",
            "copier.yml",
            "copier-template/pyproject.toml.jinja",
            "README.md",
        ],
        root,
    )
    if code:
        return code
    code = run(["git", "commit", "-m", f"chore: release {target_tag}"], root)
    if code:
        return code
    code = run(["git", "tag", "-a", target_tag, "-m", f"release {target_tag}"], root)
    if code:
        return code
    code = run(["git", "push", "origin", branch, target_tag], root)
    if code:
        return code

    print(f"released {target_tag}")
    return 0


def release_system(root: Path, version_arg: str | None) -> int:
    current_version = read_current_version(root / "iti_system" / "__about__.py")
    target_version = normalize_version(version_arg) if version_arg else bump_patch(current_version)
    target_tag = f"v{target_version}"

    if target_version == current_version:
        raise CliError(f"version already set to {target_version}")
    if not version_is_newer(current_version, target_version):
        raise CliError(f"target version must be newer than {current_version}")
    if git_output(root, ["status", "--porcelain"]).strip():
        raise CliError("working tree is not clean")

    branch = git_output(root, ["symbolic-ref", "--quiet", "--short", "HEAD"]).strip()
    if not branch:
        raise CliError("release requires a branch checkout")
    if subprocess.run(["git", "rev-parse", "--verify", "--quiet", f"refs/tags/{target_tag}"], cwd=root).returncode == 0:
        raise CliError(f"tag already exists: {target_tag}")

    code = run(["uv", "run", "pytest", "-q"], root)
    if code:
        return code

    write_system_release_files(root, target_version)

    code = run(["git", "add", "iti_system/__about__.py", "pyproject.toml", "README.md"], root)
    if code:
        return code
    code = run(["git", "commit", "-m", f"chore: release {target_tag}"], root)
    if code:
        return code
    code = run(["git", "tag", "-a", target_tag, "-m", f"release {target_tag}"], root)
    if code:
        return code
    code = run(["git", "push", "origin", branch, target_tag], root)
    if code:
        return code

    print(f"released {target_tag}")
    return 0


def git_output(root: Path, args: Sequence[str]) -> str:
    completed = subprocess.run(
        ["git", *args],
        cwd=root,
        text=True,
        stdout=subprocess.PIPE,
        stderr=subprocess.PIPE,
        check=False,
    )
    if completed.returncode:
        raise CliError(completed.stderr.strip() or f"git {' '.join(args)} failed")
    return completed.stdout


def read_current_version(about_file: Path) -> str:
    match = re.search(r'^__version__\s*=\s*"([^"]+)"', about_file.read_text(encoding="utf-8"), re.MULTILINE)
    if not match:
        raise CliError(f"version not found in {about_file}")
    return match.group(1)


def write_framework_release_files(root: Path, target_version: str) -> None:
    replace_first_line(
        root / "iti" / "__about__.py",
        lambda line: line.startswith("__version__ = "),
        f'__version__ = "{target_version}"',
    )
    replace_section_default(root / "copier.yml", "framework_tag:", f"  default: v{target_version}")
    replace_section_default(root / "copier.yml", "system_tag:", f"  default: v{target_version}")
    replace_first_line(
        root / "copier-template" / "pyproject.toml.jinja",
        lambda line: line.startswith("version = "),
        f'version = "{target_version}"',
    )
    replace_first_line(
        root / "README.md",
        lambda line: line.startswith('  "iti-flask @ git+https://git.noahlan.cn/iti-framework/iTi-Flask.git@v'),
        f'  "iti-flask @ git+https://git.noahlan.cn/iti-framework/iTi-Flask.git@v{target_version}",',
    )
    replace_first_line(
        root / "README.md",
        lambda line: line.startswith("iticli release v"),
        f"iticli release v{target_version}",
        count=2,
    )


def write_system_release_files(root: Path, target_version: str) -> None:
    replace_first_line(
        root / "iti_system" / "__about__.py",
        lambda line: line.startswith("__version__ = "),
        f'__version__ = "{target_version}"',
    )
    replace_first_line(
        root / "pyproject.toml",
        lambda line: line.startswith('iti-flask = { git = "https://git.noahlan.cn/iti-framework/iTi-Flask.git", tag = "'),
        f'iti-flask = {{ git = "https://git.noahlan.cn/iti-framework/iTi-Flask.git", tag = "v{target_version}" }}',
    )
    replace_first_line(
        root / "README.md",
        lambda line: line.startswith('  "iti-flask @ git+https://git.noahlan.cn/iti-framework/iTi-Flask.git@v'),
        f'  "iti-flask @ git+https://git.noahlan.cn/iti-framework/iTi-Flask.git@v{target_version}",',
    )
    replace_first_line(
        root / "README.md",
        lambda line: line.startswith('  "iti-system @ git+https://git.noahlan.cn/iti-framework/iTi-System.git@v'),
        f'  "iti-system @ git+https://git.noahlan.cn/iti-framework/iTi-System.git@v{target_version}",',
    )
    replace_first_line(
        root / "README.md",
        lambda line: line.startswith("iticli release v"),
        f"iticli release v{target_version}",
        count=2,
    )


def replace_first_line(path: Path, predicate: Any, new_line: str, count: int = 1) -> None:
    lines = path.read_text(encoding="utf-8").splitlines()
    updated = 0
    for index, line in enumerate(lines):
        if predicate(line):
            lines[index] = new_line
            updated += 1
            if updated == count:
                path.write_text("\n".join(lines) + "\n", encoding="utf-8")
                return
    raise CliError(f"line not updated in {path}")


def replace_section_default(path: Path, section_header: str, new_line: str) -> None:
    lines = path.read_text(encoding="utf-8").splitlines()
    in_section = False
    for index, line in enumerate(lines):
        if line == section_header:
            in_section = True
            continue
        if in_section and line and not line.startswith((" ", "\t")):
            break
        if in_section and line.startswith("  default: v"):
            lines[index] = new_line
            path.write_text("\n".join(lines) + "\n", encoding="utf-8")
            return
    raise CliError(f"line not updated in {path}")


def normalize_version(raw: str) -> str:
    major, minor, patch = parse_version(raw)
    return f"{major}.{minor}.{patch}"


def bump_patch(raw: str) -> str:
    major, minor, patch = parse_version(raw)
    return f"{major}.{minor}.{patch + 1}"


def version_is_newer(current: str, target: str) -> bool:
    return parse_version(target) > parse_version(current)


def parse_version(raw: str) -> tuple[int, int, int]:
    version = raw.removeprefix("v")
    parts = version.split(".")
    if len(parts) != 3:
        raise CliError(f"invalid version: {raw}")
    try:
        return tuple(int(part) for part in parts)  # type: ignore[return-value]
    except ValueError as exc:
        raise CliError(f"invalid version: {raw}") from exc


if __name__ == "__main__":
    raise SystemExit(main())