// ============================================================================
// Pipeline Orchestrator
// Runs all steps sequentially, tracks state, supports re-running individual steps.
// ============================================================================

import * as fs from "node:fs/promises";
import * as path from "node:path";
import { validateEstimation } from "./validators.js";
import { executeSynthesize } from "./steps/05-synthesize.js";
import { executeCritique } from "./steps/06-critique.js";
import type {
  PipelineConfig,
  PipelineInput,
  EstimationState,
  StepResult,
} from "./types.js";

export interface PipelineCallbacks {
  onStepStart?: (stepId: string, stepName: string) => void;
  onStepComplete?: (stepId: string, result: StepResult) => void;
  onStepError?: (stepId: string, error: string) => void;
}

/**
 * The main estimation pipeline orchestrator.
 * Runs steps sequentially, persists state between steps, supports re-entry.
 */
export class EstimationPipeline {
  private config: PipelineConfig;
  private state: EstimationState;
  private callbacks: PipelineCallbacks;

  constructor(config: PipelineConfig, callbacks: PipelineCallbacks = {}) {
    this.config = config;
    this.callbacks = callbacks;
    this.state = this.createInitialState();
  }

  private createInitialState(): EstimationState {
    return {
      concept: null as any, // Will be set in run()
      usage: {
        totalPromptTokens: 0,
        totalCompletionTokens: 0,
        totalCost: 0,
        perStep: [],
      },
    };
  }

  /**
   * Run the full estimation pipeline from a completed project concept.
   */
  async run(input: PipelineInput): Promise<EstimationState> {
    this.state.concept = input.concept;
    this.state.budget = input.budget;

    // Ensure output directories
    await fs.mkdir(this.config.outputDir, { recursive: true });

    // Step 5: Position synthesis
    await this.runStep("05-synthesize", "Position Descriptions", async () => {
      const result = await executeSynthesize(this.state, this.config);
      if (result.success) this.state.positionDescriptions = result.data;
      return result;
    });

    // Step 6: Quality critique
    await this.runStep(
      "06-critique",
      "Quality Gate (Industrial Critic)",
      async () => {
        const result = await executeCritique(this.state, this.config);
        if (result.success) {
          this.state.critiquePassed = result.data.passed;
          this.state.critiqueErrors =
            result.data.errors?.map((e: any) => `${e.field}: ${e.issue}`) || [];

          // Apply corrections
          if (result.data.corrections) {
            const corrections = result.data.corrections;
            // Note: We only correct the positionDescriptions since briefing/design/sitemap are locked in the concept phase.
            // If the critique suggests changes to those, it should be a warning or failure.
            if (corrections.positionDescriptions) {
              this.state.positionDescriptions = {
                ...this.state.positionDescriptions,
                ...corrections.positionDescriptions,
              };
            }
          }
        }
        return result;
      },
    );

    // Step 7: Deterministic validation
    await this.runStep("07-validate", "Deterministic Validation", async () => {
      // Build the merged form state first
      this.state.formState = this.buildFormState();
      const validationResult = validateEstimation(this.state);
      this.state.validationResult = validationResult;

      if (!validationResult.passed) {
        console.log("\n⚠️ Validation Issues:");
        for (const error of validationResult.errors) {
          console.log(`  ❌ [${error.code}] ${error.message}`);
        }
      }
      if (validationResult.warnings.length > 0) {
        console.log("\n⚡ Warnings:");
        for (const warning of validationResult.warnings) {
          console.log(`  ⚡ [${warning.code}] ${warning.message}`);
          if (warning.suggestion) console.log(`     → ${warning.suggestion}`);
        }
      }

      return {
        success: true,
        data: validationResult,
        usage: {
          step: "07-validate",
          model: "none",
          promptTokens: 0,
          completionTokens: 0,
          cost: 0,
          durationMs: 0,
        },
      };
    });

    // Save final state
    await this.saveState();

    return this.state;
  }

  /**
   * Run a single step with callbacks and error handling.
   */
  private async runStep(
    stepId: string,
    stepName: string,
    executor: () => Promise<StepResult>,
  ): Promise<void> {
    this.callbacks.onStepStart?.(stepId, stepName);
    console.log(`\n📍 ${stepName}...`);

    try {
      const result = await executor();
      if (result.usage) {
        this.state.usage.perStep.push(result.usage);
        this.state.usage.totalPromptTokens += result.usage.promptTokens;
        this.state.usage.totalCompletionTokens += result.usage.completionTokens;
        this.state.usage.totalCost += result.usage.cost;
      }

      if (result.success) {
        const cost = result.usage?.cost
          ? ` ($${result.usage.cost.toFixed(4)})`
          : "";
        const duration = result.usage?.durationMs
          ? ` [${(result.usage.durationMs / 1000).toFixed(1)}s]`
          : "";
        console.log(`  ✅ ${stepName} complete${cost}${duration}`);
        this.callbacks.onStepComplete?.(stepId, result);
      } else {
        console.error(`  ❌ ${stepName} failed: ${result.error}`);
        this.callbacks.onStepError?.(stepId, result.error || "Unknown error");
        throw new Error(result.error);
      }
    } catch (err) {
      const errorMsg = (err as Error).message;
      this.callbacks.onStepError?.(stepId, errorMsg);
      throw err;
    }
  }

  /**
   * Build the final FormState compatible with @mintel/pdf.
   */
  private buildFormState(): Record<string, any> {
    const facts = this.state.concept.auditedFacts || {};
    return {
      projectType: "website",
      ...facts,
      briefingSummary: this.state.concept.strategy.briefingSummary || "",
      designVision: this.state.concept.strategy.designVision || "",
      sitemap: this.state.concept.architecture.sitemap || [],
      positionDescriptions: this.state.positionDescriptions || {},
      websiteTopic:
        this.state.concept.architecture.websiteTopic ||
        facts.websiteTopic ||
        "",
      statusQuo: facts.isRelaunch ? "Relaunch" : "Neuentwicklung",
      name: facts.personName || "",
      email: facts.email || "",
    };
  }

  /**
   * Save the full state to disk for later re-use.
   */
  private async saveState(): Promise<void> {
    const timestamp = new Date().toISOString().replace(/[:.]/g, "-");
    const companyName =
      this.state.concept.auditedFacts?.companyName || "unknown";

    // Save full state
    const stateDir = path.join(this.config.outputDir, "json");
    await fs.mkdir(stateDir, { recursive: true });

    const statePath = path.join(stateDir, `${companyName}_${timestamp}.json`);
    await fs.writeFile(
      statePath,
      JSON.stringify(this.state.formState, null, 2),
    );
    console.log(`\n📦 Saved state to: ${statePath}`);

    // Save full pipeline state (for debugging / re-entry)
    const debugPath = path.join(
      stateDir,
      `${companyName}_${timestamp}_debug.json`,
    );
    await fs.writeFile(debugPath, JSON.stringify(this.state, null, 2));

    // Print usage summary
    console.log("\n──────────────────────────────────────────────");
    console.log("📊 PIPELINE USAGE SUMMARY");
    console.log("──────────────────────────────────────────────");
    for (const step of this.state.usage.perStep) {
      if (step.cost > 0) {
        console.log(
          `  ${step.step}: ${step.model} — $${step.cost.toFixed(6)} (${(step.durationMs / 1000).toFixed(1)}s)`,
        );
      }
    }
    console.log("──────────────────────────────────────────────");
    console.log(`  TOTAL: $${this.state.usage.totalCost.toFixed(6)}`);
    console.log(
      `  Tokens: ${(this.state.usage.totalPromptTokens + this.state.usage.totalCompletionTokens).toLocaleString()}`,
    );
    console.log("──────────────────────────────────────────────\n");
  }

  /** Get the current state (for CLI inspection). */
  getState(): EstimationState {
    return this.state;
  }

  /** Load a saved state from JSON. */
  async loadState(jsonPath: string): Promise<void> {
    const raw = await fs.readFile(jsonPath, "utf8");
    const formState = JSON.parse(raw);
    this.state.formState = formState;
  }
}