const std = @import("std");
const testing = std.testing;
const src = @import("src");
const Config = src.Config;

test "config file validation" {
    // Test various config file contents
    const test_configs = [_]struct {
        content: []const u8,
        should_be_valid: bool,
        description: []const u8,
    }{
        .{
            .content =
            \\server:
            \\  host: "localhost"
            \\  port: 8080
            \\auth:
            \\  enabled: true
            \\storage:
            \\  type: "local"
            \\  path: "/tmp/ml_experiments"
            ,
            .should_be_valid = true,
            .description = "Valid complete config",
        },
        .{
            .content =
            \\server:
            \\  host: "localhost"
            \\  port: 8080
            ,
            .should_be_valid = true,
            .description = "Minimal valid config",
        },
        .{
            .content = "",
            .should_be_valid = false,
            .description = "Empty config",
        },
        .{
            .content =
            \\invalid_yaml: [
            \\  missing_closing_bracket
            ,
            .should_be_valid = false,
            .description = "Invalid YAML syntax",
        },
    };

    for (test_configs) |case| {
        // For now, just verify the content is readable
        try testing.expect(case.content.len > 0 or !case.should_be_valid);

        if (case.should_be_valid) {
            try testing.expect(std.mem.indexOf(u8, case.content, "server") != null);
        }
    }
}

test "config default values" {
    const allocator = testing.allocator;

    // Create minimal config
    const minimal_config =
        \\server:
        \\  host: "localhost"
        \\  port: 8080
    ;

    // Verify config content is readable
    const content = try allocator.alloc(u8, minimal_config.len);
    defer allocator.free(content);

    @memcpy(content, minimal_config);

    try testing.expect(std.mem.indexOf(u8, content, "localhost") != null);
    try testing.expect(std.mem.indexOf(u8, content, "8080") != null);
}

test "config server settings" {
    const allocator = testing.allocator;
    _ = allocator; // Mark as used for future test expansions

    // Test server configuration validation
    const server_configs = [_]struct {
        host: []const u8,
        port: u16,
        should_be_valid: bool,
    }{
        .{ .host = "localhost", .port = 8080, .should_be_valid = true },
        .{ .host = "127.0.0.1", .port = 8080, .should_be_valid = true },
        .{ .host = "example.com", .port = 443, .should_be_valid = true },
        .{ .host = "", .port = 8080, .should_be_valid = false },
        .{ .host = "localhost", .port = 0, .should_be_valid = false },
        .{ .host = "localhost", .port = 65535, .should_be_valid = true },
    };

    for (server_configs) |config| {
        if (config.should_be_valid) {
            try testing.expect(config.host.len > 0);
            try testing.expect(config.port >= 1 and config.port <= 65535);
        } else {
            try testing.expect(config.host.len == 0 or
                config.port == 0 or
                config.port > 65535);
        }
    }
}

test "config authentication settings" {
    const allocator = testing.allocator;
    _ = allocator; // Mark as used for future test expansions

    // Test authentication configuration
    const auth_configs = [_]struct {
        enabled: bool,
        has_api_keys: bool,
        should_be_valid: bool,
    }{
        .{ .enabled = true, .has_api_keys = true, .should_be_valid = true },
        .{ .enabled = false, .has_api_keys = false, .should_be_valid = true },
        .{ .enabled = true, .has_api_keys = false, .should_be_valid = false },
        .{ .enabled = false, .has_api_keys = true, .should_be_valid = true }, // API keys can exist but auth disabled
    };

    for (auth_configs) |config| {
        if (config.enabled and !config.has_api_keys) {
            try testing.expect(!config.should_be_valid);
        } else {
            try testing.expect(true); // Valid configuration
        }
    }
}

test "config storage settings" {
    const allocator = testing.allocator;
    _ = allocator; // Mark as used for future test expansions

    // Test storage configuration
    const storage_configs = [_]struct {
        storage_type: []const u8,
        path: []const u8,
        should_be_valid: bool,
    }{
        .{ .storage_type = "local", .path = "/tmp/ml_experiments", .should_be_valid = true },
        .{ .storage_type = "s3", .path = "bucket-name", .should_be_valid = true },
        .{ .storage_type = "", .path = "/tmp/ml_experiments", .should_be_valid = false },
        .{ .storage_type = "local", .path = "", .should_be_valid = false },
        .{ .storage_type = "invalid", .path = "/tmp/ml_experiments", .should_be_valid = false },
    };

    for (storage_configs) |config| {
        if (config.should_be_valid) {
            try testing.expect(config.storage_type.len > 0);
            try testing.expect(config.path.len > 0);
        } else {
            try testing.expect(config.storage_type.len == 0 or
                config.path.len == 0 or
                std.mem.eql(u8, config.storage_type, "invalid"));
        }
    }
}

test "config file paths" {
    const allocator = testing.allocator;

    // Test config file path resolution
    const config_paths = [_][]const u8{
        "config.yaml",
        "config.yml",
        ".ml/config.yaml",
        "/etc/ml/config.yaml",
    };

    for (config_paths) |path| {
        try testing.expect(path.len > 0);

        // Test path joining
        const joined = try std.fs.path.join(allocator, &.{ "/base", path });
        defer allocator.free(joined);

        try testing.expect(joined.len > path.len);
        try testing.expect(std.mem.startsWith(u8, joined, "/base/"));
    }
}

test "config environment variables" {
    const allocator = testing.allocator;
    _ = allocator; // Mark as used for future test expansions

    // Test environment variable substitution
    const env_vars = [_]struct {
        key: []const u8,
        value: []const u8,
        should_be_substituted: bool,
    }{
        .{ .key = "ML_SERVER_HOST", .value = "localhost", .should_be_substituted = true },
        .{ .key = "ML_SERVER_PORT", .value = "8080", .should_be_substituted = true },
        .{ .key = "NON_EXISTENT_VAR", .value = "", .should_be_substituted = false },
    };

    for (env_vars) |env_var| {
        if (env_var.should_be_substituted) {
            try testing.expect(env_var.value.len > 0);
        }
    }
}

test "config validation errors" {
    const allocator = testing.allocator;

    // Test various validation error scenarios
    const error_scenarios = [_]struct {
        config_content: []const u8,
        expected_error_type: []const u8,
    }{
        .{
            .config_content = "invalid: yaml: content: [",
            .expected_error_type = "yaml_syntax_error",
        },
        .{
            .config_content = "server:\n  port: invalid_port",
            .expected_error_type = "type_error",
        },
        .{
            .config_content = "",
            .expected_error_type = "empty_config",
        },
    };

    for (error_scenarios) |scenario| {
        // For now, just verify the content is stored correctly
        const content = try allocator.alloc(u8, scenario.config_content.len);
        defer allocator.free(content);

        @memcpy(content, scenario.config_content);

        try testing.expect(std.mem.eql(u8, content, scenario.config_content));
    }
}

test "config hot reload" {
    const allocator = testing.allocator;

    // Initial config
    const initial_config =
        \\server:
        \\  host: "localhost"
        \\  port: 8080
    ;

    // Updated config
    const updated_config =
        \\server:
        \\  host: "localhost"
        \\  port: 9090
    ;

    // Test config content changes
    const initial_content = try allocator.alloc(u8, initial_config.len);
    defer allocator.free(initial_content);

    const updated_content = try allocator.alloc(u8, updated_config.len);
    defer allocator.free(updated_content);

    @memcpy(initial_content, initial_config);
    @memcpy(updated_content, updated_config);

    try testing.expect(std.mem.indexOf(u8, initial_content, "8080") != null);
    try testing.expect(std.mem.indexOf(u8, updated_content, "9090") != null);
    try testing.expect(std.mem.indexOf(u8, updated_content, "8080") == null);
}