"""
Procedural scenario generator for the CI/CD Doctor environment.
"""

import random

from .packages import get_packages

PYTHON_VERSIONS = ["3.9", "3.10"]       # always wrong; correct is 3.11
REQUIRED_ENV_VARS = ["DATABASE_URL", "API_KEY", "SECRET_KEY"]
WRONG_PORTS = [3000, 5000, 9000]
WRONG_TEST_COMMANDS = [
    "python -m pytest tests/ --collect-only",   # collects but never runs
    "python -m unittest discover tests/",        # wrong runner
    "python -m pytest tests/ --dry-run",         # dry-run, no output
]


def generate_easy_scenario(seed: int) -> dict:
    """
    Returns a filesystem dict + answer_key.
    The filesystem has requirements.txt missing one required package.
    """
    rng = random.Random(seed)
    all_packages = get_packages("easy")
    missing = rng.choice(all_packages)
    present = [p for p in all_packages if p != missing]

    return {
        "filesystem": {
            "requirements.txt": "\n".join(present) + "\n",
            "pipeline.yaml": "stages:\n  - install\n",
            "logs/install.log": "",
            "app.py": "import flask\nimport numpy\n# app code here\n",
        },
        "answer_key": {
            "fixes": {
                "requirements.txt": missing,
            },
        },
    }

def _medium_type_a(rng: random.Random, all_packages: list) -> dict:
    """
    Type A: wrong Python version (Dockerfile) + missing env var (.env.ci).
    Pipeline: install → env_check → docker_build
    Both files must be fixed. install always passes.
    """
    wrong_version = rng.choice(PYTHON_VERSIONS)
    missing_var = rng.choice(REQUIRED_ENV_VARS)
    present_vars = {v: "placeholder" for v in REQUIRED_ENV_VARS if v != missing_var}
    env_ci_content = "".join(f"{k}={v}\n" for k, v in sorted(present_vars.items()))

    return {
        "filesystem": {
            "requirements.txt": "\n".join(all_packages) + "\n",
            "Dockerfile": (
                f"FROM python:{wrong_version}-slim\n"
                "WORKDIR /app\n"
                "COPY requirements.txt .\n"
                "RUN pip install -r requirements.txt\n"
                "COPY . .\n"
                'CMD ["python", "app.py"]\n'
            ),
            ".env.ci": env_ci_content,
            "pipeline.yaml": "stages:\n  - install\n  - env_check\n  - docker_build\n",
            "app.py": "import flask\n# app code here\n",
            "logs/install.log": "",
        },
        "answer_key": {
            "fixes": {
                "Dockerfile": "python:3.11",
                ".env.ci": missing_var,
            },
        },
    }


def _medium_type_b(rng: random.Random, all_packages: list) -> dict:
    """
    Type B: missing package (requirements.txt) + deployment flag off (deploy_config.yml).
    Pipeline: install → config_validate → smoke_test
    install fails first; after fixing, config_validate fails.
    """
    missing_pkg = rng.choice(all_packages)
    present_pkgs = [p for p in all_packages if p != missing_pkg]

    return {
        "filesystem": {
            "requirements.txt": "\n".join(present_pkgs) + "\n",
            "deploy_config.yml": (
                "target_env: production\n"
                "deploy_enabled: false\n"   # BUG: must be true
                "replicas: 2\n"
                "health_check_path: /health\n"
                "timeout: 30\n"
            ),
            "pipeline.yaml": "stages:\n  - install\n  - config_validate\n  - smoke_test\n",
            "app.py": "import flask\n# app code here\n",
            "logs/install.log": "",
        },
        "answer_key": {
            "fixes": {
                "requirements.txt": missing_pkg,
                "deploy_config.yml": "deploy_enabled: true",
            },
        },
    }


def _medium_type_c(rng: random.Random, all_packages: list) -> dict:
    """
    Type C: wrong test command (Makefile) + missing env var (.env.ci).
    Pipeline: install → env_check → test
    env_check fails first; after fixing, test fails due to bad Makefile.
    """
    wrong_cmd = rng.choice(WRONG_TEST_COMMANDS)
    missing_var = rng.choice(REQUIRED_ENV_VARS)
    present_vars = {v: "placeholder" for v in REQUIRED_ENV_VARS if v != missing_var}
    env_ci_content = "".join(f"{k}={v}\n" for k, v in sorted(present_vars.items()))

    return {
        "filesystem": {
            "requirements.txt": "\n".join(all_packages) + "\n",
            ".env.ci": env_ci_content,
            "Makefile": (
                ".PHONY: test\n"
                "test:\n"
                f"\t{wrong_cmd}\n"
            ),
            "pipeline.yaml": "stages:\n  - install\n  - env_check\n  - test\n",
            "app.py": "import flask\n# app code here\n",
            "logs/install.log": "",
        },
        "answer_key": {
            "fixes": {
                ".env.ci": missing_var,
                "Makefile": "python -m pytest tests/",
            },
        },
    }


def _medium_type_d(rng: random.Random, all_packages: list) -> dict:
    """
    Type D: wrong port (service.yaml) + wrong Python version (Dockerfile).
    Pipeline: install → port_check → docker_build
    port_check fails first; after fixing, docker_build fails.
    install always passes.
    """
    wrong_version = rng.choice(PYTHON_VERSIONS)
    wrong_port = rng.choice(WRONG_PORTS)

    return {
        "filesystem": {
            "requirements.txt": "\n".join(all_packages) + "\n",
            "Dockerfile": (
                f"FROM python:{wrong_version}-slim\n"
                "WORKDIR /app\n"
                "COPY requirements.txt .\n"
                "RUN pip install -r requirements.txt\n"
                "COPY . .\n"
                'CMD ["python", "app.py"]\n'
            ),
            "service.yaml": (
                "apiVersion: v1\n"
                "kind: Service\n"
                "metadata:\n"
                "  name: app\n"
                "spec:\n"
                f"  port: {wrong_port}\n"
            ),
            "pipeline.yaml": "stages:\n  - install\n  - port_check\n  - docker_build\n",
            "app.py": "import flask\n# app code here\n",
            "logs/install.log": "",
        },
        "answer_key": {
            "fixes": {
                "service.yaml": "port: 8080",
                "Dockerfile": "python:3.11",
            },
        },
    }


def generate_medium_scenario(seed: int) -> dict:
    """
    Randomly selects one of four structurally distinct medium scenario types,
    then generates the specifics (which var, which version, etc.) from the
    same seed. Same seed → same scenario every time.
    """
    rng = random.Random(seed)
    all_packages = get_packages("medium")
    scenario_type = rng.choice(["A", "B", "C", "D"])

    if scenario_type == "A":
        return _medium_type_a(rng, all_packages)
    elif scenario_type == "B":
        return _medium_type_b(rng, all_packages)
    elif scenario_type == "C":
        return _medium_type_c(rng, all_packages)
    else:
        return _medium_type_d(rng, all_packages)


def _hard_type_a(rng: random.Random, all_packages: list) -> dict:
    """
    Type A: ci.yml ordering → Dockerfile alpine → numpy version pin.
    Pipeline: ci_validate → docker_build(strict) → install(hard).
    """
    _ = rng  # reserved for future per-seed variation
    requirements_lines = [
        "numpy==1.21" if pkg == "numpy" else pkg
        for pkg in all_packages
    ]

    return {
        "filesystem": {
            "requirements.txt": "\n".join(requirements_lines) + "\n",
            "Dockerfile": (
                "FROM python:3.11-alpine\n"
                "WORKDIR /app\n"
                "COPY requirements.txt .\n"
                "RUN pip install -r requirements.txt\n"
                "COPY . .\n"
                'CMD ["python", "app.py"]\n'
            ),
            "ci.yml": "stages: test, build, install\n",
            "pipeline.yaml": "stages:\n  - ci_validate\n  - docker_build\n  - install\n",
            "app.py": "import flask\nimport numpy\n# app code here\n",
            "logs/install.log": "",
        },
        "answer_key": {
            "fixes": {
                "ci.yml": "install, build, test",
                "Dockerfile": "python:3.11-slim",
                "requirements.txt": "numpy==1.26",
            },
        },
    }


def _hard_type_b(rng: random.Random, all_packages: list) -> dict:
    """
    Type B: ci.yml ordering → missing env var → wrong test command.
    Pipeline: ci_validate → env_check → test.
    requirements.txt is clean; no Dockerfile needed.
    """
    wrong_cmd = rng.choice(WRONG_TEST_COMMANDS)
    missing_var = rng.choice(REQUIRED_ENV_VARS)
    present_vars = {v: "placeholder" for v in REQUIRED_ENV_VARS if v != missing_var}
    env_ci_content = "".join(f"{k}={v}\n" for k, v in sorted(present_vars.items()))

    return {
        "filesystem": {
            "requirements.txt": "\n".join(all_packages) + "\n",
            "ci.yml": "stages: test, build, install\n",
            ".env.ci": env_ci_content,
            "Makefile": (
                ".PHONY: test\n"
                "test:\n"
                f"\t{wrong_cmd}\n"
            ),
            "pipeline.yaml": "stages:\n  - ci_validate\n  - env_check\n  - test\n",
            "app.py": "import flask\n# app code here\n",
            "logs/install.log": "",
        },
        "answer_key": {
            "fixes": {
                "ci.yml": "install, build, test",
                ".env.ci": missing_var,
                "Makefile": "python -m pytest tests/",
            },
        },
    }


def _hard_type_c(rng: random.Random, all_packages: list) -> dict:
    """
    Type C: Dockerfile alpine → deploy disabled → wrong service port.
    Pipeline: docker_build(strict) → config_validate → port_check.
    """
    _ = rng  # reserved for future per-seed variation
    wrong_port = rng.choice(WRONG_PORTS)

    return {
        "filesystem": {
            "requirements.txt": "\n".join(all_packages) + "\n",
            "Dockerfile": (
                "FROM python:3.11-alpine\n"
                "WORKDIR /app\n"
                "COPY requirements.txt .\n"
                "RUN pip install -r requirements.txt\n"
                "COPY . .\n"
                'CMD ["python", "app.py"]\n'
            ),
            "deploy_config.yml": (
                "target_env: production\n"
                "deploy_enabled: false\n"
                "replicas: 2\n"
                "health_check_path: /health\n"
                "timeout: 30\n"
            ),
            "service.yaml": (
                "apiVersion: v1\n"
                "kind: Service\n"
                "metadata:\n"
                "  name: app\n"
                "spec:\n"
                f"  port: {wrong_port}\n"
            ),
            "pipeline.yaml": "stages:\n  - docker_build\n  - config_validate\n  - port_check\n",
            "app.py": "import flask\n# app code here\n",
            "logs/install.log": "",
        },
        "answer_key": {
            "fixes": {
                "Dockerfile": "python:3.11-slim",
                "deploy_config.yml": "deploy_enabled: true",
                "service.yaml": "port: 8080",
            },
        },
    }


def _hard_type_d(rng: random.Random, all_packages: list) -> dict:
    """
    Type D: missing package → missing env var → Dockerfile alpine.
    Pipeline: install(hard) → env_check → docker_build(strict).
    """
    missing_pkg = rng.choice(all_packages)
    present_pkgs = [p for p in all_packages if p != missing_pkg]
    missing_var = rng.choice(REQUIRED_ENV_VARS)
    present_vars = {v: "placeholder" for v in REQUIRED_ENV_VARS if v != missing_var}
    env_ci_content = "".join(f"{k}={v}\n" for k, v in sorted(present_vars.items()))

    return {
        "filesystem": {
            "requirements.txt": "\n".join(present_pkgs) + "\n",
            ".env.ci": env_ci_content,
            "Dockerfile": (
                "FROM python:3.11-alpine\n"
                "WORKDIR /app\n"
                "COPY requirements.txt .\n"
                "RUN pip install -r requirements.txt\n"
                "COPY . .\n"
                'CMD ["python", "app.py"]\n'
            ),
            "pipeline.yaml": "stages:\n  - install\n  - env_check\n  - docker_build\n",
            "app.py": "import flask\n# app code here\n",
            "logs/install.log": "",
        },
        "answer_key": {
            "fixes": {
                "requirements.txt": missing_pkg,
                ".env.ci": missing_var,
                "Dockerfile": "python:3.11-slim",
            },
        },
    }


def generate_hard_scenario(seed: int) -> dict:
    """
    Randomly selects one of four structurally distinct hard scenario types,
    then generates the specifics from the same seed. Each variant is a
    three-fix cascading failure — each pipeline run stops at the first
    failing stage, so bugs surface one at a time as the agent fixes them.
    Same seed → same scenario every time.
    """
    rng = random.Random(seed)
    all_packages = get_packages("hard")
    scenario_type = rng.choice(["A", "B", "C", "D"])

    if scenario_type == "A":
        return _hard_type_a(rng, all_packages)
    elif scenario_type == "B":
        return _hard_type_b(rng, all_packages)
    elif scenario_type == "C":
        return _hard_type_c(rng, all_packages)
    else:
        return _hard_type_d(rng, all_packages)